National Hurricane Center
The fifth named tropical storm of the 2012 Atlantic hurricane season formed on Thursday, the U.S. National Hurricane Center said.
Named Ernesto, it had sustained winds of 50 mph and was 295 miles east of the Caribbean's Windward Islands.
Tropical storm warnings were in place for Barbados, Dominica, Guadeloupe, St. Lucia and St. Vincent.
"Some slight strengthening is forecast during the next 48 hours," the center said in its advisory. It did not forecast whether Ernesto would grow into a hurricane.
Most of the Windward Islands by Friday can expect 2-3 inches of rain, with some areas getting 5 inches, it added.
The storm was on a path that could take it into the Gulf of Mexico next week.
The Atlantic hurricane season has started slowly, with the last tropical storm being Debby a month ago. It drenched Florida and eight deaths were tied to the storm.
U.S. government forecasters in May predicted a "normal" 2012 season, saying 9-15 named storms could be expected. Between 4-8 of those were predicted to become hurricanes.
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